Since the mailbag contains this article: http://www.straightdope.com/mailbag/mmicroboil.html
I thought I would post this here. Does anyone know of a story relating to this on one of the Dateline/20-20 type shows last week. I got into a pretty heated (sic) argument with my MIL about this and commited a sin: I said the words “nucleation site” at a family dinner.
Anyway, MIL claims that they interviewed the woman who got burned in the face and that that they showed the mark on the ceiling where the fork hit, which I assume meant it was shot out of the mug.
Actually, I can accept the part about getting burned in the face, but I refuse to believe that a piece of table ware can be launched out of a mug.
Did anyone see this. Let me cynically add, who is the woman suing?
Saw the DateLine show you are referring to. Apparently a scientific fact. They actually conducted a laboratory experiment to duplicate and demonstrate the effect of superheated water. Requires a set of specific conditions to occur. ie extremely smooth container like glass or ceramic and microwave conditions where all the water is heated at a constant rate. These conditions suppress the boiling action. Water apparently requires some kind of turbulance to start the boiling process. The smooth container has little or no entrapped air particles on the surface therefore no air bubbles rise to surface which starts the boiling process. Furthermore the boiling process is repressed by the even heating of the water. There is no circulation of hot water from the bottom rising to the top while the cool top water sinks to the bottom. The demo they setup was approx 3/4 cup of water placed in glass container and placed in microwave for several minutes cook time. Upon removal there was no apparent “boiling action”, a fork was gingerly tossed into the cup and it literally exploded at least 3 ft straight up and some of it even splashed on the shirt of Stone Phillips and he was stand AT LEAST 3 feet from the cup.
I know that microwaves can superheat water. Of course, in the demonstration, what did they put in the water to color it? It could very well have raised the boiling point and made matters much worse.
